scons: Don't globally define WIN32_LEAN_AND_MEAN.

Some of the demo progams legitimately need the functionality
that's disabled by WIN32_LEAN_AND_MEAN.

Instead the solution should be to define WIN32_LEAN_AND_MEAN just before
including windows.h on a case by case basis.

scons/gallium.py

@@ -153,8 +153,6 @@ def generate(env):
             #'UNICODE',
             ('_WIN32_WINNT', '0x0501'), # minimum required OS version
             ('WINVER', '0x0501'),
-            # http://msdn2.microsoft.com/en-us/library/6dwk3a1z.aspx,
-            'WIN32_LEAN_AND_MEAN',
         ]
         if msvc and env['toolchain'] != 'winddk':
             cppdefines += [

scons/generic.py

@@ -228,8 +228,6 @@ def generate(env):
             '_WINDOWS',
             #'_UNICODE',
             #'UNICODE',
-            # http://msdn2.microsoft.com/en-us/library/6dwk3a1z.aspx,
-            #'WIN32_LEAN_AND_MEAN',
         ]
         if msvc:
             cppdefines += [

src/gallium/state_trackers/wgl/SConscript

@@ -11,10 +11,11 @@ if env['platform'] in ['windows']:
     	'.',
     ])
      
-    env.Append(CPPDEFINES = [
+    env.AppendUnique(CPPDEFINES = [
         '_GDI32_', # prevent wgl* being declared __declspec(dllimport)
         'BUILD_GL32', # declare gl* as __declspec(dllexport) in Mesa headers 
         'WIN32_THREADS', # use Win32 thread API
+        'WIN32_LEAN_AND_MEAN', # http://msdn2.microsoft.com/en-us/library/6dwk3a1z.aspx
     ])
      
     sources = [